Piezoelectric ignition apparatus

ABSTRACT

A compact and accurately-operable piezoelectric ignition apparatus comprising a case, a piezoelectric element fixed on one side of the case by a fixing covering, a hammer and a first spring both arranged coaxially with the piezoelectric element, a hammer pressing plate, a support member, the hammer pressing plate and the support member being joined rotatably in an inverted-V shape at an end each thereof, and a pressure plate, the other end of the support member being attached to the case, the pressure plate having a free end in contact with the joint between the support member and the hammer pressing plate, the hammer having a protrusion which engages with and disengages from the other end of the hammer pressing plate as the pressure plate is depressed.

United States Patent 11 1 Okamoto Aug. 7, 1973 [54] PIEZOELECTRIC IGNITION APPARATUS 3,350,608 lO/l967 Maltner et al. 3lO/8.7 X [75] Inventor. gsgangl Okamoto, Mor1guch1-sh1, Primary Examinerej. D. Miller Assistant Examiner-Mark O. Budd [73] Assignee: Matsushita Electric Industrial C0., Attarney. Richard K, Stevens, Robert J, Frank et al Ltd., Osaka, Japan 122 Filed: Jan. 31, 1972 [571 ABSTRACT A com act and accurately-operable iezoelectric igni- [Zll Appl' 222207 tion ap paratus comprising a case, a piezoelectric element fixed on one side of the case by a fixing covering, [30] Foreign Application Priority Data a hammer and a first spring both arranged coaxially Feb, 2, 1971 Japan 46/4652 with the Piezoelectric element, a hammer Pressing plate, a support member, the hammer pressing plate 52 us. or. 3l0/8.7 and the Support member being joined rotaiably in an 51 1111. C1 ll04r 17/00 inverted-V Shape at an end each thereof, and a Pressure 58 Field of Search 310/83, 8.7, 9.1; Plate, the other end of the pp member being 317/D1G H 81, 315/55, 209 p2 tached to the case, the pressure plate having a free end in contact with the joint between the support member 5 References Cited and the hammer pressing plate, the hammer having a UNITED STATES PATENTS protrusion which engages with and disengages from the other end of the hammer pressing plate as the pressure 3,466,474 9/1969 Ochrar 310/8] plate is depressed 3,475,654 10/1969 Ochiai et al. 3,564,341 2/1971 Nishiura BIO/8.7 X 3 Claims, 4 Drawing Figures 1 PIEZOIELECTRIC IGNITION APPARATUS The present invention relates to a piezoelectric ignition device, and an object thereof is to provide a small piezoelectric device which is capable of ignition operations with high accuracy.

The ignition device according to the present invention comprises a case, a piezoelectric element fixed on one side of said case by means of a fixing covering, a hammer and a first spring both arranged coaxially with said piezoelectric element, a hammer pressing plate, a support member, said hammer pressing plate and said support member being joined rotatably in an inverted- V shape at an end each thereof, and a pressure plate,

the other end of said support member being attached to said case, said pressure plate having a free end in contact with the joint between said support member and said hammer pressing plate, said hammer having a protrusion which engages with and disengages from the other end of said hammer pressing plate as said pressure plate is depressed.

The above and other objects, features and advantages will be made apparent by the detailed description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a diagram showing a front view of an embodiment of the present invention;

FIG. 2 is an enlarged front view of the embodiment of FIG. 1 showing a partial section thereof previous to its operation;

FIG. 3 shows an enlarged front view of the same embodiment in operation; and

FIG. 4 shows a perspective view of the same embodiment from which the pressure plate is removed.

The piezoelectric device according to the present invention will be now explained with reference to the accompanying drawings. The reference numeral 1 shows a pizoelectric element fixed on one side of a chamber 4 having a fixed covering 3 in a case 2. The numeral 5 shows a hammer contained in the same chamber 4 and maintained pressed in contact with the piezoelectric element 1 by means of a spring 6 disposed on the right hand side thereof. The hammer 5 is provided with an engaging protrusion 7 which projects through the aperture 8 of the fixed covering 3, the fixed covering 3 having a pair of sloped portions 9 adjacent to the aperture 8. The numeral 10 shows a plate for pressing the hammer 5 and provided with an engaging portion 11 for engagement with the protrusion 7 of the hammer 5. The numeral 12 shows a curved support for holding the plate 10, and an end of the curved support 12 is attached to the case 2, and end of the engaging portion 11 of the plate 10 being rotatably mounted on the other end of the curved support 12.

When pressure is applied to that end of the engaging portion 11 which engages with the support 12, the engaging portion ll rotates to its horizontal position thereby pressing the engaging protrusion 7. The hammer pressing plate 10 is fitted with a spring 13 which has a greater restitution force than another spring attached to the plate 14 described later. The pressure plate 14 has a free end opposed to that end of the engaging portion 11 of the hammer pressing plate 10 which is held by the curve'support 12. The pressure plate 14 is adapted to return to its original position by means of the spring 15. The numeral 16 shows a lead wire. The numeral 17 shows a roller fitted in the joint between the engaging portion 11 of the hammer pressing plate 10 and the curved support 12.

The operation of the device according to the present invention with the above described construction will be now explained.

The pressing of the free end of the pressure plate 14 causes the engaging portion, that is, a free end of the engaging portion 11 of the hammer pressing plate 10 to flatten into its horizontal position, whereby the free end of the engaging portion 11 which does not engage with the support 12 is pressed into contact with the engaging protrusion 7. In the process, the curved support 12 of the hammer pressing plate 10 rotates around the lower end thereof for the smooth mechanical operation of the hammer pressing plate 10.

Even though the hammer 5 is pressed against the force of the spring 6, the engagement of the protrusion 7 with the engaging portion 11 is released as the end of the engaging portion 11 slides up the sloped portions 9, as shown in FIG. 3, so that hammer 5 is pushed back to its original position by the spring 6, striking the piezoelectric element 1. To ensure engagement and disengagement of the protrusion 7 with the engaging portion 11, spring 15 is also adapted to keep the engaging portion 11 in contact with the fixed covering 3 as shown in FIG. 3. As a result, a spark due to piezoelectricity is generated thereby igniting an ignition gas not shown.

According to the present invention, the hammer pressing plate 10 which is opposed to the pressure plate 14 is arranged at a relatively small angle with the horizontal line, and therefore the apparatus can be made low in height. In addition, the circular motion of the support 12 of the hammer pressing plate 10 which occurs when pressure is applied to the apparatus permits smooth ignition. Further, since the free end of the pressure plate 14 is in contact with an end of the engaging portion 11 of the hammer pressing plate 10, the engaging portion 11 operates without fail when the free end of the pressure plate 14 is depressed, thereby assuring accurate ignition.

What is claimed is:

l. A piezoelectric ignition apparatus comprising a case, a piezoelectric element fixed on one side of said case by means ofa fixing covering, a hammer and a first spring both arranged coaxially with said piezoelectric element, a hammer pressing plate, a support member, a hinged joint between said hammer pressing plate and said support member, said hammer pressing plate and said support member being rotatably joined at one end thereof in an inverted V-shape, and a pressure plate, said support member and said hammer pressing plate being rotatable about the joint therebetween, the other end of the support member being joined rotatably to said case by means of a hinge, said pressure plate having a free end in contact with the hinged joint between said support member and said hammer pressing plate and another end hinged to said casing, said hammer having a protrusion which engages with and disengages from other end of said hammer pressing plate as said pressure plate is depressed.

2. A piezoelectric ignition apparatus according to claim 1, further comprising a second spring interposed between said pressure plate and said hammer pressing plate thereby assuring the engagement and disengagement of said protrusion of said hammer with and from said other end of said hammer pressing plate.

3. A piezoelectric ignition apparatus according to claim 1, further comprising a second return spring interposed betwen said case and said support member, said return spring being adapted to return said support member and said hammer pressing plate to their original positions after the depression of said pressure plate. 4 k 8 i 

1. A piezoelectric ignition apparatus comprising a case, a piezoelectric element fixed on one side of said case by means of a fixing covering, a hammer and a first spring both arranged coaxially with said piezoelectric element, a hammer pressing plate, a support member, a hinged joint between said hammer pressing plate and said support member, said hammer pressing plate and said support member being rotatably joined at one end thereof in an inverted V-shape, and a pressure plate, said support member and said hammer pressing plate being rotatable about the joint therebetween, the other end of the support member being joined rotatably to said case by means of a hinge, said pressure plate having a free end in contact with the hinged joint between said support member and said hammer pressing plate and another end hinged to said casing, said hammer having a protrusion which engages with and disengages from other end of said hammer pressing plate as said pressure plate is depressed.
 2. A piezoelectric ignition apparatus according to claim 1, further comprising a second spring interposed between said pressure plate and said hammer pressing plate thereby assuring the engagement and disengagement of said protrusion of said hammer with and from said other end of said hammEr pressing plate.
 3. A piezoelectric ignition apparatus according to claim 1, further comprising a second return spring interposed betwen said case and said support member, said return spring being adapted to return said support member and said hammer pressing plate to their original positions after the depression of said pressure plate.
 4. A piezoelectric ignition apparatus according to claim 1, in which said fixing covering has a sloped portion and said other that-end of the hammer pressing plate which is adapted to engage with said protrusion of said hammer slides up said sloped portion as said pressure plate is depressed, whereby said other end of said hammer pressing plate disengages from said protrusion of said hammer.
 5. A piezoelectric ignition apparatus according to claim 1, in which said fixing covering is provided with a guide aperture for controlling the motion of said hammer. 